Brush



March 10, 1959 G. G. STEWART 2,876,477

' I BRUSH Filed Dec. 8. 1955 FIG I illl l2 IO/ l2 Q) I F/GfZ FIG. 5 Fla. 6 FIG. 7

IN VEN TOR. GEORGE G. STEWART MAM ATTORNEY.

The present invention relates to brushes, and more particularly, to brushes having greater cleaning ability because of the shape and nature of the bristles. In the preferred embodiment of the present invention, the brush comprises a toothbrush capable of achieving maximum cleansing action when applied to human teeth.

The superiority for brushing purposes of natural bristles over synthetic bristles has long been appreciated by those skilled in the brush art, particularly in the art of manufacturing toothbrushes. Thus, the need for synthetic bristles capable of performing favorably when compared to natural bristles has been accentuated in recent years due to the curtailment of supplies of natural bristle which originates in China and Manchuria. However, even the natural bristles suflfer from serious drawbacks which are desirable to overcome. The quality of natural bristles varies from lot to lot, as would be expected in a natural product. Moreover, the color and general appearance of natural bristle cannot be closely regulated.

While the reasons for the efficacy of animal bristles, such as hog bristles, and in particular, the superior grades of hog bristles originating in China and Manchuria are not completely understood, it has been suggested that natural bristles possess superior brushing qualities because their surface roughness and scaly nature tend to remove surface particles. Moreover, animal bristles tend to facilitate the keratinization of the gums when used for massage, their scaly nature aiding this purpose. Attempts have therefore been made to duplicate the surface roughness of natural bristles as by roughening the exterior surface of synthetic bristles. However, such synthetic bristles have not proven satisfactory.

The use of multifilament synthetic bristles has also been suggested, but such bristles are relatively difficult to manufacture.

This invention has as an object the provision of a synthetic monofllament bristle having superior cleansing characteristics.

This invention has as another object the provision of a brush of superior cleansing characteristics, which may be readily and cheaply manufactured.

These and other objects are accomplished by the brush of the present invention in which bristles are provided having at least three and preferably from four to ten fluted sides. Each of the bristles is formed from a synthetic monofilament, such as nylon (a co-polymer of hexamethylenediamine and adipic acid), Lucite (a methyl methacrylate polymer), cellulose acetate, cellulose acetate butyrate, polymerized vinyl acetate, etc. By fluted as used herein is meant providing the sides of the bristle with concave or inwardly arcuate contours. The fluted sides of the bristle function in a manner analogous to scaly natural bristles.

0 By forming the brush bristles as aforesaid, the bristles 1 "v ay be closely packed in a hole within the brush. The n interstices between the brush bristles will be in the shape arcuate irregular figures, with the interstices set olf by 1 the toothed or barbed corners of the bristle sides. The

2,876,477 Patented Mar. 10, 1959 corners of the bristle sides serve as scrapers for the bristles, the collected material being removed through the arcuately walled passageways formed by the interstices. The brush may be used for cleansing, and for coating and painting, the interstices forming channels through which the paint may be passed.

When the brush bristles of my invention are incorporated into toothbrushes, such toothbrushes possess all of the advantages of toothbrushes formed from natural bristles. Moreover, such toothbrushes possess the advantages concomitant with synthetic bristles, namely uniformly of quality, color, size, etc.

Preferably, the brush bristles of the present invention comprise fluted regular polygons, namely polygons of symmetrical cross-section, such as fluted squares, pentagons, hexagons, heptagons, octagons, nonagons and the like. However, non-symmetrical and irregular polygons having at least three and preferably four or more sides, each of which are fluted, may also be used.

While I do not wish to be bound by any theory as to why the brushes formed from the bristles of my invention perform more efficiently than prior brush embodiments, it is my belief that this is due to the presence of the spaced scraping edges coupled with a suction-cup eliect produced by the flattening of the bristle sides against the surface being brushed.

For the purpose of illustrating the invention there are shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

Referring to the drawings wherein like reference characters refer to like parts:

Figure 1 is an elevational view of a brush embodiment of the present invention.

Figure 2 is a plan view of the brush embodiment shown in Figure 1.

Figure 3 is an enlarged cross-sectional view of an embodiment of a brush bristle in accordance with the present invention.

Figure 4 is an enlarged cross-sectional view of another embodiment of a brush bristle in accordance with the present invention.

Figure 5 is an enlarged cross-sectional view of yet another embodiment of a brush bristle in accordance with the present invention.

Figure 6 is an enlarged cross-sectional view of a further embodiment of a brush bristle of the present invention.

Figure 7 is an enlarged cross-sectional view of a yet further embodiment of a brush bristle of the present lnvention.

Figure 8 is a fragmentary cross-sectional view through a portion of a tuft of bristles from a brush embodiment of the present invention.

Referring initially to Figures 1 and 2, one embodiment designated 10 of the brush of the present invention is shown therein. While the brush embodiment 10 shown in Figures 1 and 2 is a toothbrush, it is, of course, to be understood that the brush of the present invention may be employed for other purposes, the arrangement of the tufts may be varied, and the length of the brush bristles within a single tuft may likewise be varied to accomplish specific purposes. In particular, the brushes of my invention are of optimum utility for the purpose of cleansing brushes, and especially where the removal of tenacious dirt, film or scale deposits is desired.

The brush 10 includes a handle portion 12 and a body portion 14 having a plurality of tuft receiving holes 16. In each of holes 16 is tightly packed and secured a tuft 18 formed of a plurality of bristles whose description is set forth more fully below. The extension of the tufts 18 beyond body portion 14 and the configuration of the free ends of the tufts may be varied to accommodate to particular purposes and uses.

A plurality of eight-sided bristles 20 having fluted sides are shown in the tuft collection shown in Figure 8, with a cross-sectional view through an individual bristle 20 being shown in Figure 7.

The bristles of the present invention are formed of a monofilament, and as heretofore noted my be formed from a variety of plastic materials, preferably by extruding the plastic through dies having the necessary configuration to result in monofilament bristles having the desired fluted shape.

By constructing each bristle of a single filament, greater strength and more efficient brushing action. can be achieved than by uniting a plurality of filaments together in a sheath.

In Figure 3 there is shown a bristle 22 comprising a fluted four-sided regular polygon.

In Figure 4 there is shown a bristle 24 comprising a fluted five-sided regular polygon.

In Figure 5 there is shown a bristle 26 comprising a fluted six-sided regular polygon.

In Figure 6 there is shown a bristle 28 comprising a fluted seven-sided regular polygon.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. A toothbrush including a body portion having formed therein a plurality of tuft-receiving holes, a tuft of bristles in each hole, each tuft comprising a plurality of closely packed bristles, each of said bristles being formed from a synthetic monofilament, each of said bristles having the cross-section of a polygon, all of the sides of each of said polygonally cross-sectioned bristles having a concave contour, the apices of the cross-section of said bristles being adjacent each other, with the sides of said bristles defining relatively large interstices intermediate said bristles and relatively small interstices intermediate said bristles, with the relatively large interstices being separated from each other by the relatively small interstices.

2. A toothbrush in accordance with claim 1 in which the bristles have the cross-section of a regular polygon.

3. A toothbrush in accordance with claim 2 in which each of the bristles has the cross-section of a regular octagon.

References Cited in the file of this patent UNITED STATES PATENTS 1,773,969 Dreyfus Aug. 26, 1930 2,250,112 Larson July 22, 1941 2,317,485 Rider Apr. 27, 1943 2,443,055 Reis June 8, 1948 

